My mod 6530 has the colt collapsible stock, is all colt, no bayo lug, and practically as new. Don't know what the condition of yours is, but, even with a fixed stock and well used, $850 seems a helluva buy. BTW...Sporter Lightweight serial # SL027246 and below is pre-ban.
Gunbroker.com had one listed for $2400 or so and got no bites. Check prebanarms.com also ... He gets top $ but the merchandise is top condition. Stay Safe